• Fire Science and Engineering
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• v.25 no.4
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• pp.89-93
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• 2011

It is not recommended that elevator use for egress at (super) high rise buildings because elevator shaft main roles to spread of fire smoke. But in North America used to protect this area by elevator shaft pressurization. These tests are performed at high rise apartment to verify that elevator shaft pressurization can protect to spread of fire smoke or not. and verify to used for egress at fire. Pressurization at elevator shaft make pressure difference of 50 Pa all floor at 150 CMM because this method have low friction loss from air flow. Also when dwelling door and elevator door are opened that critical velocity is performed to protect of back-layering from fire room for escape routs by 180 CMM. Therefore through out these pressurization tests by elevator shaft are estimated to have less overpressure because supply air difference are low between to satisfy critical velocity at one door opened and maintain to pressure difference all doors closed. Finally we verified that disable or residual people can use elevator for egress at fire by elevator shaft pressurization.

• Journal of Chest Surgery
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• v.19 no.3
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• pp.443-448
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• 1986

Aortic dissection is a serious disease that mortality does not approach to zero despite of medical and surgical improvement. Recently two cases of aortic dissection were treated with good results by the two other methods. Case 1 [57-Y-0-Male]; Chief complaint was chest pain radiating to the back. Preoperatively he was controlled by Minipress, dichlotride, & sodium nitroprusside. Aortography showed DeBakey Type III aortic dissection extending from just below the Lt. subclavian artery to the proximal portion of the origin of the renal artery. Through the midline long incision Flow reversal & Thrombo-exclusion method was used, and bypass course was proximal anastomosis at the ascending aorta - through the Rt. thoracic cavity - midportion of the diaphragm - posterior to the liver, stomach, & pancreas - distal anastomosis at the abdominal aorta proximal to its bifurcation. Bypass graft was preclotted 20 mm Dacron Woven Graft, and the aortic arch between the Lt. subclavian artery & Lt. common carotid artery was divided and meticulously sutured. Control aortogram which was done at 4th postoperative month revealed obstruction of the false lumen by thrombosis, and complications were not noticed. Case 2 [53-Y-0-Male]; Chief complaint was chest pain radiating to the abdomen. DeBakey Type III aortic dissection which was similar to the case 1 was detected by the aortography, and involvement of the Lt. subclavian & common carotid arteries was suspicious. Through the Lt. posterolateral thoracotomy the Ringed Intraluminal Sutureless Graft, No. 22 mm, was inserted from just below the Lt. common carotid artery to the midportion of the descending thoracic aorta under total circulation arrest using a F-F bypass, and the Lt. subclavian artery was ligated. Postoperatively hospital course was uneventful with antihypertensive drugs, and any specific complications were not noticed.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.523-523
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• 2012

As the wafer geometric requirements continuously complicated and minutes in tens of nanometers, the expectation of real-time add-on sensors for in-situ plasma process monitoring is rapidly increasing. Various industry applications, utilizing plasma impedance monitor (PIM) and optical emission spectroscopy (OES), on etch end point detection, etch chemistry investigation, health monitoring, fault detection and classification, and advanced process control are good examples. However, process monitoring in semiconductor manufacturing industry requires non-invasiveness. The hypothesis behind the optical monitoring of plasma induced ion current is for the monitoring of plasma induced charging damage in non-invasive optical way. In plasma dielectric via etching, the bombardment of reactive ions on exposed conductor patterns may induce electrical current. Induced electrical charge can further flow down to device level, and accumulated charges in the consecutive plasma processes during back-end metallization can create plasma induced charging damage to shift the threshold voltage of device. As a preliminary research for the hypothesis, we performed two phases experiment to measure the plasma induced current in etch environmental condition. We fabricated electrical test circuits to convert induced current to flickering frequency of LED output, and the flickering frequency was measured by high speed optical plasma monitoring system (OPMS) in 10 kHz. Current-frequency calibration was done in offline by applying stepwise current increase while LED flickering was measured. Once the performance of the test circuits was evaluated, a metal pad for collecting ion bombardment during plasma etch condition was placed inside etch chamber, and the LED output frequency was measured in real-time. It was successful to acquire high speed optical emission data acquisition in 10 kHz. Offline measurement with the test circuitry was satisfactory, and we are continuously investigating the potential of real-time in-situ plasma induce current measurement via OPMS.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.52-57
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• 2005

The increasing automobiles continue to cause air-pollution problem s worse than ever. In fact, many automobile research are involved in how to reduce exhaust emissions effectively specially in $NO_X$ and PM to comply with stringent emission standards, Euro V. This research emphasized on the development of continuous regeneration DPF technology which was one of promising removing technology of particulate matters because of its comparability and high applicability. In addition, this research discussed on some design points of view through correlation study by com paring the experimental data with computational results by the introduction of commercial codes such as CFD-ACE+ and KIVA-3V. The numerical simulation on the performance of continuous regeneration DPF apparatus and corresponding emission characteristics has been predicted well enough and verified with experimental results. The pressure and average temperatures are decreased to about 2.6% and 1.4% respectively under a full engine load condition mainly due to back pressures raised by diesel particulate filter. Pressure, temperature and heat releasing rates tend to decrease specially at higher engine load, but they are not affected at lower engine load regions.

• Journal of Sensor Science and Technology
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• v.13 no.3
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• pp.218-223
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• 2004

Thin film gas sensor based on tin oxide was fabricated and its characteristics were examined. Target gas is acetonitrile ($CH_{3}CN$) that is simulant gas of blood agent gas. Sensing materials are $SnO_{2}$, $SnO_{2}$/Pt, and (Sn/Pt)oxidation with thickness from $1000{\AA}$ to $3000{\AA}$. Sensor was consisted of sensing electrode with interdigit (IDT) type in front side and a heater in back side. Its dimension was $7{\times}10{\times}0.6mm^{3}$. Fabricated sensor was measured as flow type and monitored real time using PC. The optimal sensing material for $CH_{3}CN$ was {Sn($3000{\AA}$)/Pt($30{\AA}$)}oxidation and its sensitivity and operating temperature were 30%, $300^{\circ}C$ in $CH_{3}CN$ 3 ppm.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.70-80
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• 2007

This study was surveyed from January to september, 2007 in order to evaluate the function of coastal wetland as a ecological axis in korea peninsula. Assessment was done by RAM (Rapid Assessment Method). RAM is consisted of total 8 contents and divided into high, moderate, low. The preservation grade of RAM is divided into 4 grades; absolute preservation, preservation, improvement and improvement or restoration. Throughout survey on total 14 wetlands of marine, estuary wetland and back marsh which are distributed in west coast in chung-nam province, their function was assessed. As result, total all the 14 wetlands were judged as preservation grade by assessment of 8 functional contents. The function of wetlands assessed as preservation grade showed high in water quality protection and improvement. Also, showed high in vegetation diversity, wildlife habitat and aesthetic recreation. Meanwhile, showed low in ground water recharge, Shoreline/Stream Bank Protection, Flood/Stormwater storage and Flood flow alteration. Of wetlands evaluated as preservation grade, Dae-ho, Sinduri, Bu-Nam lake, Sowhang dune and keum river estuary were assessed as absolute preservative area owing to habitation of international protection species and endangered species. These wetlands are essential to be managed continuously as a area having high ecological value. Farther, this wetlands will be done as a axis of ecological network related to land ecosystem.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12S
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• pp.1217-1223
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• 2003

Nerve gas sensor based on tin oxide was fabricated and its characteristics were examined. Target gas is dimethyl methyl phosphonate(C$_3$ $H_{9}$ $O_3$P, DMMP) that is simulant gas of nerve gas. Sensing materials were Sn $O_2$ added a-Al$_2$ $O_3$ with 0∼20wt.% and were physically mixed each material. They were deposited by screen printing method on alumina substrate. The sensor device was consisted of sensing electrode with interdigit(IDT) type in front and a heater in back side. Total size of device was 7${\times}$10${\times}$0.6㎣. Crystallite size & phase identification and morphology of fabricated Sn $O_2$ powders were analyzed by X-ray diffraction and by a scanning electron microscope, respectively. Fabricated sensor was measured as flow type and resistance change of sensing material was monitored as real time using LabVIEW program. The best sensitivity was 75% at adding 4wt.% $\alpha$-Al$_2$ $O_3$, operating temperature 30$0^{\circ}C$ to DMMP 0.5ppm. Response and recovery time were about 1 and 3min., respectively. Repetition measurement was very good with $\pm$3％ in full scale.TEX>$\pm$3％ in full scale.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1203-1204
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• 2006

Recently, utility network is getting more and more complicated and huge. In addition to, demands of power conversion devices which have non-linear switching devices are getting more and more increased. Consequently, according to the non-linear power semiconductor devices, current harmonics are unavoidable. Those current harmonics flow back to utility network and become one of the reasons which make the voltage distortion. On the other hands, voltage sag from sudden increasing loads is also one of the terrible problems inside of utility network. In order to compensate the current harmonics and voltage sag problem, AF(Active Filter) systems could be a good solution method and SMES(Superconducting Magnetic Energy Storage) system is a very good promising source due to the high response time of charge and discharge. Therefore, the combined system of AF and SMES is a wonderful device to compensate both harmonics current and voltage sag. However, unfortunately SMES needs a superconducting magnetic coil. Because of the introduction of superconducting magnetic coil, quench problem caused by unexpected reasons is always existed. In case of discharge operation, quench is a significantly harmful factor according as it decreases the energy capacity of SMES. Therefore, this paper presents a decision method of the specification of the AF-SMES system considering internal fault condition. Especially, authors analyzed the change of the original energy capacity of SMES regarding to the size of resistance caused by quench of superconducting magnetic coil. Finally, based on this simulation, authors manufactured actual Active Filter System using DSP.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.133-142
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• 2008

AGV systems are widely used to increase the flexibility and the efficiency of the material handling systems. AGV systems are one of critical factors which determine the overall performance of the manufacturing systems. To this end, the optimal design for AGV systems is essential. Commercial simulation software is often used as an analysis tool during the design of AGV systems, however a series of procedures are desirable to simplify the analysis processes. In this paper, we present and develop the architecture for unidirectional AGV systems simulator which is able to consider approximate optimal unidirectional flow path and various operational parameters. The designed AGV systems simulator is based on JAVA, and it is developed to support designing approximate optimal unidirectional network by using Tabu search method. In addition, it enables users to design and evaluate AGV systems and to analyze alternative solutions easily. Simulation engine is consists of layout designer, AGV operation plan designer, and integrated AGVS layout designer. Users enter their system design/operation information into input window, then the entered information is automatically utilized for modeling and simulating AGV systems in simulation engine. By this series of procedures, users can get the feed back quickly.

• Membrane Journal
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• v.27 no.1
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• pp.77-83
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• 2017

Transient behavior of fouling resistance was observed with a laboratory-scaled, submerged microfiltration membrane system treating high-turbidity source water consisting of inorganic silica particles and humic acid. Fouling mitigation efficiency with inorganic silica particles caused by aeration was reduced significantly as both humic acid and calcium ion existed together. Scanning electron microscopic observations showed that humic acid was adsorbed onto the surface of inorganic silica particles in the presence of calcium. Turbidity removal was achieved almost completely by submerged MF system regardless of feed compositions. However, the $UV_{254}$ removal of humic acid was improved in the presence of both calcium and inorganic silica particles. Additionally, increasing air-flow rate tended to increase $UV_{254}$ removal efficiency higher than 80%. This may be caused by back-transport of humic acid enhanced by inorganic silica particles providing surface for organic adsorption in the presence of calcium.